Zentron Crystal Collection: Rough Ruby Sapphire Stones - Raw Pieces in Velvet Bag (1 Pound)

Rubies and sapphires are a variety of the mineral corundum. In their pure form, they are red in color. Impurities in the stones can make them blue, orange, yellow, green, or purple. In their blue form, the stones are known as sapphires, while all the other colors are "fancy sapphires." Ruby's red color comes from its mineral content of Chromium. The more in the stone, the darker the red. Blue colors come from iron and titanium. Ruby is the birthstone of July. It is very hard stone with a mohs of 9.0, making it one of the hardest gems known